1. Field of the Invention
The present invention relates to an image forming technique of forming an image on a print medium.
2. Description of the Related Art
As a technique of correcting density nonuniformity, Japanese Patent Laid-Open No. 02-286341 (reference 1) discloses a technique of, when printing an image, detecting density nonuniformity of printing elements at a predetermined timing, and adjusting, based on the detection result, a driving signal to be supplied to a printhead.
Japanese Patent Laid-Open No. 2000-52571 (reference 2: U.S. Pat. No. 6,707,579) discloses a technique of detecting density nonuniformity of a test image formed by driving a printhead in accordance with binary image data for test, generating density nonuniformity correction data on the basis of the detection result, and correcting binary image data before forming an image.
However, the technique disclosed in reference 1 corrects image data when the number of print sheets reaches a predetermined value or the OFF period reaches a predetermined value. This technique cannot correct image data in real time.
The technique disclosed in reference 2 corrects binary image data before forming an image, and cannot correct density nonuniformity suddenly occurring when forming an image. For this reason, this technique cannot correct binary image data in real time.